<template>
  <div class="cart">
    <h4>全部商品</h4>
    <div class="cart-main">
      <div class="cart-th">
        <div class="cart-th1">全部</div>
        <div class="cart-th2">商品</div>
        <div class="cart-th3">单价（元）</div>
        <div class="cart-th4">数量</div>
        <div class="cart-th5">小计（元）</div>
        <div class="cart-th6">操作</div>
      </div>
      <div class="cart-body">
        <ul class="cart-list" v-for="cart in cartList" :key="cart.id">
          <li class="cart-list-con1">
            <!-- 
              普通input value属性和input事件
              单选或多选 checked属性和change事件
              下拉列表 value属性和change事件
             -->
            <input
              type="checkbox"
              name="chk_list"
              :checked="cart.isChecked"
              @change="
                handleIsCheckedChange(cart.skuId, $event, cart.isChecked)
              "
            />
          </li>
          <li class="cart-list-con2">
            <img :src="cart.imgUrl" />
            <div class="item-msg">
              {{ cart.skuName }}
            </div>
          </li>
          <li class="cart-list-con4">
            <span class="price">{{ cart.cartPrice }}</span>
          </li>
          <li class="cart-list-con5">
            <!-- 
              v-model 绑定value属性和input自定义事件
              @input="handleSkuNumChange" 再次绑定自定义input事件

              不管是自定义事件还是DOM事件，都可以绑定多个回调函数
                这多个回调函数会依次触发

              $event  
                简单理解：event对象
                真正理解：代表事件回调函数的第一个参数（触发事件传入的第一个参数）
                  DOM事件中，事件回调函数的第一个参数是event对象，所以$event就是event对象
                  自定义事件中，触发事件传入的第一个参数，$event就是第一个参数的值

              下面$event就是skuNum最新的值，cart.skuNum旧值
             -->
            <InputNumber
              :value="cart.skuNum"
              @input="handleSkuNumInput($event, cart.skuNum, cart.skuId)"
            />
          </li>
          <li class="cart-list-con6">
            <span class="sum">{{ cart.cartPrice * cart.skuNum }}</span>
          </li>
          <li class="cart-list-con7">
            <a class="sindelet" @click="delCart(cart.skuId)">删除</a>
            <br />
          </li>
        </ul>
      </div>
    </div>
    <div class="cart-tool">
      <div class="select-all">
        <input class="chooseAll" type="checkbox" v-model="allChecked" />
        <span>全选</span>
      </div>
      <div class="option">
        <a @click="batchDelCart">删除选中的商品</a>
      </div>
      <div class="money-box">
        <div class="chosed">
          已选择
          <span> {{ isCheckedNum }} </span>
          件商品
        </div>
        <div class="sumprice">
          <em>总价（不含运费） ：</em>
          <i class="summoney">{{ totalPrice }}</i>
        </div>
        <div class="sumbtn">
          <router-link class="sum-btn" to="/trade">结算</router-link>
        </div>
      </div>
    </div>
  </div>
</template>

<script>
import { mapActions, mapState } from "vuex";
import debounce from "lodash/debounce";
import InputNumber from "@/components/InputNumber";

export default {
  name: "ShopCart",
  components: {
    InputNumber,
  },
  mounted() {
    this.getCartList();
  },
  methods: {
    ...mapActions("shopcart", [
      "getCartList",
      "updateCartSkuNum",
      "updateCartIsChecked",
      "delCart",
      "batchDelCart",
      "batchCheckCart",
    ]),
    // 数量
    handleSkuNumInput: debounce(function (newSkuNum, oldSkuNum, skuId) {
      // action函数只能接受一个参数
      this.updateCartSkuNum({
        newSkuNum,
        oldSkuNum,
        skuId,
      });
    }, 500),
    // 单选
    handleIsCheckedChange: debounce(function (skuId, e, oldIsChecked) {
      const isChecked = +e.target.checked;
      if (isChecked === oldIsChecked) return;
      this.updateCartIsChecked({
        skuId,
        isChecked,
      });
    }, 500),
  },
  computed: {
    ...mapState("shopcart", ["cartList"]),
    // 全选&全不选
    allChecked: {
      get() {
        return this.cartList.every((cart) => cart.isChecked);
      },
      set(val) {
        const isChecked = +val;
        this.batchCheckCart(isChecked);
      },
    },
    // 已选择商品数量
    isCheckedNum() {
      return this.cartList.reduce((p, c) => {
        return p + (c.isChecked ? c.skuNum : 0);
      }, 0);
    },
    // 总价
    totalPrice() {
      return this.cartList.reduce((p, c) => {
        return p + (c.isChecked ? c.skuNum * c.cartPrice : 0);
      }, 0);
    },
  },
};
</script>

<style lang="less" scoped>
.cart {
  width: 1200px;
  margin: 0 auto;
  h4 {
    margin: 9px 0;
    font-size: 14px;
    line-height: 21px;
  }
  .cart-main {
    .cart-th {
      background: #f5f5f5;
      border: 1px solid #ddd;
      padding: 10px;
      overflow: hidden;
      & > div {
        float: left;
      }
      .cart-th1 {
        width: 25%;
        input {
          vertical-align: middle;
        }
        span {
          vertical-align: middle;
        }
      }
      .cart-th2 {
        width: 25%;
      }
      .cart-th3,
      .cart-th4,
      .cart-th5,
      .cart-th6 {
        width: 12.5%;
      }
    }
    .cart-body {
      margin: 15px 0;
      border: 1px solid #ddd;
      .cart-list {
        padding: 10px;
        border-bottom: 1px solid #ddd;
        overflow: hidden;
        & > li {
          float: left;
        }
        .cart-list-con1 {
          width: 5%;
        }
        .cart-list-con2 {
          width: 45%;
          img {
            width: 82px;
            height: 82px;
            float: left;
          }
          .item-msg {
            float: left;
            margin: 0 10px;
          }
        }
        .cart-list-con4 {
          width: 10%;
        }
        .cart-list-con5 {
          width: 17%;
          .mins {
            border: 1px solid #ddd;
            border-right: 0;
            float: left;
            color: #666;
            width: 6px;
            text-align: center;
            padding: 8px;
            text-decoration: none;
          }
          input {
            border: 1px solid #ddd;
            width: 40px;
            height: 31px;
            float: left;
            text-align: center;
            font-size: 14px;
          }

          .plus {
            border: 1px solid #ddd;
            border-left: 0;
            float: left;
            color: #666;
            width: 6px;
            text-align: center;
            padding: 8px;
            text-decoration: none;
          }
        }

        .cart-list-con6 {
          width: 10%;

          .sum {
            font-size: 16px;
          }
        }

        .cart-list-con7 {
          width: 13%;

          a {
            color: #666;
          }
        }
      }
    }
  }
  .cart-tool {
    overflow: hidden;
    border: 1px solid #ddd;

    .select-all {
      padding: 10px;
      overflow: hidden;
      float: left;

      span {
        vertical-align: middle;
      }

      input {
        vertical-align: middle;
      }
    }

    .option {
      padding: 10px;
      overflow: hidden;
      float: left;

      a {
        float: left;
        padding: 0 10px;
        color: #666;
      }
    }

    .money-box {
      float: right;

      .chosed {
        line-height: 26px;
        float: left;
        padding: 0 10px;
      }

      .sumprice {
        width: 200px;
        line-height: 22px;
        float: left;
        padding: 0 10px;

        .summoney {
          color: #c81623;
          font-size: 16px;
        }
      }

      .sumbtn {
        float: right;
        a {
          display: block;
          position: relative;
          width: 96px;
          height: 52px;
          line-height: 52px;
          color: #fff;
          text-align: center;
          font-size: 18px;
          font-family: "Microsoft YaHei";
          background: #e1251b;
          overflow: hidden;
          text-decoration: none;
          &hover {
            color: white !important;
          }
        }
      }
    }
  }
}
</style>
